The Breguet Classique 5157: a review

History, details and review of the ultra-flat Breguet 5157, and other Classique models.

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Model history and context

The Breguet 5157 was first presented at the Baselworld international watch fair in 2005, as a time-only, ultra-slim dress wristwatch.

Breguet Classique 5157BB

Here is how the piece is introduced on the Breguet website:

Extra-thin Classique wristwatch in 18-carat yellow gold. Self-winding movement. Silvered gold dial, hand-engraved on a rose-engine. Sapphire caseback. Water-resistant.

It succeeds the Breguet 5130, which was produced around the year 2000.
The Classique 5130 uses almost the same movement as the 5157, minus the newer high-tech enhancements, and has a smaller diameter at 35 mm instead of 38 mm for its younger sibling.
The 5130 also bears a plain gold caseback, while the 5157 has a transparent caseback, following a trend which has spread to most high-end watchmakers — although both movements certainly received the same level of attention.

The Classique 5157 comes in yellow gold (reference 5157BA) and white gold (reference 5157BB), and exclusively with a silver “guilloché” dial.
A strict two-hand watch, it can be considered as one of the simplest current Classique models. This relative sobriety is emphasized by its streamlined design, though it probably cannot be viewed as minimalistic because of its numerous details in finishing and its relatively large size.

It is still sold in 2014, at the time of writing.

The Classique collection

Breguet’s emblematic “Classique” line-up is composed of watches following the classic codes of brand founder Abraham-Louis Breguet’s designs, and manufactured in the fine tradition of Swiss watchmaking.

Breguet Classique 5157BA

Breguet is one of the oldest house names in horology, established in 1775, and its founder has contributed many important inventions to the world of watchmaking which are still in use today.
Present day’s Montres Breguet has the ambition to perpetuate its ancestor’s legacy as an innovator. Therefore, the Classique collection benefits from the latest technological enhancements developed by the manufacture.

This series of timepieces are exclusively made in a choice of precious metals: usually solid white gold, yellow gold or rose gold, and sometimes platinum for a few models.

A Breguet Classique is a synonym for timeless beauty, ingenuity, and superlative horological craft.

Case design

An elegant slim watch

Among the Classique collection, the main peculiarity of the 5157 is certainly its slim, relatively elongated profile.
Of course, there are actually slimmer pieces in the watch world, but most of them are not automatic. As you know, the winding rotor of an automatic watch takes up a proportionately large place inside the movement; and since this weight is made to move within the case, it is a defining element of its whole architecture.
Here we have an automatic watch with dimensions usually only achievable with a manual-wind or quartz movement.

As you might expect given its thinness, the 5157 is very light, especially for a solid gold watch: its weight amounts to 32 g with the strap and tang buckle.

The case diameter is quite generous nonetheless, following a tendency observed across all of the brand’s line-ups (note that most of Breguet’s Tradition or Classique Complication models now exceed 40 mm). Yet one could say that the 5157 looks even larger than its actual size, because of its thin bezel widening the diameter of the flat crystal and dial.
The dimensions of the round, fully polished case are 38 × 5.35 mm, from which extend long, welded parallel lugs — another Breguet hallmark.

3/4 profil No illustration yet.

I feel that the yellow gold has just a little bit of a reddish hue, which makes the case tone very slightly warmer than the usual yellow gold.

The case is waterproof to 3 bar (30 meters / 100 feet), ensuring that the internals of the watch stay dry in most normal situations, like in a humid climate or in a light rain.
Nevertheless, it would be wise to keep it away from water, at least out of consideration for the strap.

A true “Classique

The design of the Classique 5157 conjures up images of some of Abraham-Louis Breguet’s pocket watches from the early 19th century (like the № 4270). With those blue hands across the silver guilloché dial, round case and roman numerals on the hour chapter, the 5157 is unmistakably a Breguet!

Cannelures + crown No illustration yet.

Getting closer, one can admire the very delicate vertical caseband fluting (also known as coined edge or cannelé case) which the brand has become famous for.

This coined edge on the caseband is crafted through several steps including machining, kinematic hardening, stamping and cold-rolling. It is then hand finished.
(Please note that only Breguet knows the exact process, which is kept secret.)

The non–screw-down crown is signed with a raised B. The straight, slim lugs seem outstandingly long, and add to the character of the timepiece. Their cross section being square, they are also the only flat surface of the watch catching the light.
Like all Classique wristwatches, the underside of the lugs has a rounded tip. You may notice that the lugs of the 5157 are thinner than most of the other Classique models’, and therefore their rounded profile is also less perceptible.

Straps and buckles

The original Breguet straps for this model are 20 mm wide between the lugs, and taper at 16 mm at the buckle.
No Breguet metal bracelet has been developed for it; this must be the reason why the original watch box is designed to hold the watch flat.
The lugs of the 5157 use screw pins (instead of the more standard spring bars) to keep the strap in place. Some other Breguet models use an additional safety screw under the lugs to hold the main pin, but the lugs of the 5157 are probably too slim to accommodate this system.

Lugs or buckle? No illustration yet.

The Breguet 5157 originally comes with a tang-type buckle made of solid gold to match the case. Naturally, it can be fitted a Breguet deployant clasp in its stead (as an option), which uses the same straps as the other buckle.
The tang buckle is quite understated — unsigned and polished, with a distinctive semi-rounded shape and protruding shoulder pits for the screws.

The strap is very nice and soft, handmade from American alligator skin (also known as alligator mississippiensis). It is slightly domed, yet thin enough to match the 5157 flawlessly.
As of 2014 Breguet usually pairs yellow gold and rose gold watches with brown straps, and white gold watches with black straps in their brochures and boutiques. This choice is probably made to set off the case’s metal color.
Of course these shades are only a suggestion, as you actually have a nice collection of different OEM straps to choose from.

The hallmarks

Whether yellow or white, gold is rarely used pure. What we call 18k gold (18 karats out of a total of 24 = 75%) is an alloy of pure gold and other meticulously selected metals which make it stronger, and may purposefully alter its color.
Let us consider the two case options for the 5157:

Hallmarks are a time-honored way to assert the purity and provenance of a piece made in one or several precious metals. Those inscriptions are formed on the case itself by the means of steel stamps, which are officially registered.
In conformance with the Hallmarking Convention, the case of the Breguet 5157 carries the 4 regulatory types of stamps:

The Common Control Mark
It consists of a balance scale and 750 written between the weighing pans.
The corresponding fineness in Arabic numerals
The case has a number 750 written next to the control mark. My tang buckle does not hold exactly the same hallmarks: it is Au750 (where Au is the chemical element symbol for gold).
The registered responsibility mark
The maker’s mark is also called “poinçon de maître”. On my particular watch, it is an enigmatic “Sté (circle swirl) B” which could mean Société Breguet (in lieu of the actual name, Montres Breguet SA). Yet somehow it would look curious that the brand is not disclosing its name clearly with the stamp. Blancpain, despite being in the same group, logically uses the brand’s logo as maker’s mark.
Note that this phenomenon is probably not that uncommon; a mark “Sté E” can be found in François-Paul Journe’s cases.
The circle swirl looks like the “spiral spring” symbol watchmakers used to engrave in the back of the timepiece when they replaced the mainspring of said piece. However this code isn’t much in use since the beginning of the 20th century, and has probably no link to the actual hallmark.
On at least one other example of a Breguet 5157, the mark represents a hammer-head containing the number 115, leading us to the Favre & Perret SA case maker. The company, located in La Chaux-de-Fonds (canton of Neuchâtel, Northeast of Switzerland) has been part of the Swatch Group since 1999.
The assay office mark
The assay office mark on my specimen depicts a St. Bernard’s head, which is a giant mountain rescue dog from the Swiss Alps. It is the official hallmark of Switzerland since 1995. On the right of the dog’s head is a C letter, which points to the particular La Chaux-de-Fonds assay office.
Note that my buckle also has the Swiss hallmark, but with the tiny letter T indicating it was assayed in Chiasso (canton of Ticino, South of Switzerland), which is another of the 10 Swiss assay offices.

A tasteful dial

At a glance

The dial design of the Classique models is not only driven by aesthetic concerns, but also based on Abraham-Louis Breguet’s researches toward attaining an optimal legibility with his timepieces. This is notably reflected in his careful use of contrasting dial surfaces, as well as the distinctive shape of the hands. While this does not look very critical on a time-only watch (with no complications), this is very valuable for distinguishing the different zones on which sweep the various hands used in complicated watches.

In a pure Breguet style, the dial of the 5157 is therefore clearly separated in sections: here we have the chapter ring (brushed) which is set apart from the rest of the dial (guilloché).

Front shot of dial No illustration yet.

The dial is made from a single piece of solid yellow gold which is engine-turned (undergoing different operations) and silver plated. While this process is presumably not exactly the one used by the brand’s founder back in his time (Abraham-Louis usually worked with a piece of silver instead), it is not uncommon nowadays among high-end luxury timekeepers.

As said before, the Breguet 5157 is a strict two-hand watch. Combined with its rather large diameter, the simplicity of the Breguet 5157 is almost insolent, and the wide, uncluttered face tends to make the watch look larger than it is — even more so because the dial color is silver (as a darker color would give the impression of a smaller surface).
The clean lines of the watch are further emphasized by the symmetry of the dial; also, this geometrical aspect is a tad unusual on a Breguet Classique.

Breguet traditionally uses Roman numerals for guilloché dials. Like the majority of Roman dials, the fourth number is written as IIII instead of IV (as the additional strokes help visually counterbalance the cumbersome VIII on the opposite side of the hour chapter). The only written elements are the Breguet brand name (in a serifed, all-capitalized font) and a group of a few numerals, also called “single number” by Breguet, corresponding to the unique production number. Both are located in separate curved cartouches, respectively positioned at 12 and 6 o’clock. The numerals act as the serial number of the watch in the sense that no two watches of this model will bear the same number. Having them on the dial is an exclusive detail, even in the high-end watch world. Note that they are also engraved on the case-back.
The dial uses applied gold cabochons for the hour markers, which is surprising for an ultra-flat watch as they add some height (consider that the minute hand has to move above them).

Secret signature No illustration yet.

The dial also features Breguet’s “secret signature”, which is actually visible with the naked eye, especially with a horizontal lighting. This type of signature was already used by Abraham-Louis Breguet, who faced the problem of counterfeit watches bearing his name, and appeared as early as 1794.
Nowadays it is not uncommon to use a tiny, hidden mark to ensure the authenticity of a piece, and a few watch brands use it on a regular basis. It usually consists of a pattern which is so small and delicate that most counterfeiters would overlook it, or simply not attempt to replicate it.

Among the brands which have one such mark, let us cite Cartier (the brand name is written as part of the Roman numerals), Omega and Rolex (by the means of a minute etching in the crystal), and Breitling (with a B engraved in the bezel of certain watches). But as far as I know, only Breguet’s signature is hand made, using a pantograph, which is a device able to draw homothetic shapes by reducing the scale of the original motif.
There is such a signature on each side of the XII numeral on the hour chapter of the reference 5157.

The art of guilloché

Breguet dials have a well-deserved reputation of being beautiful, and this one is no exception. The face of the 5157 is a true celebration of guillochage.
This French noun defines a particular type of geometric ornamental engraving, which involves the use of a machine (called an ornamental lathe) to finely reproduce repetitious patterns. Guillochage requires the tip of a fine chisel to draw lines into a surface by removing material from it. As such, guillochage is not to be confused with stamping, where no material is mechanically removed.

Chapter ring close-up No illustration yet.

Thanks to its rather large diameter, a significant continuous part of the dial of the 5157 is devoted to the “Paris stud” guilloché pattern, also called hobnail pattern.
The brand name chapter and unique number chapter being decentered respectively to the top and bottom, the hands seem to be floating in an ethereal sea of guilloché.

The dial proudly yet discreetly shows the words “Guilloché main”, which translate to “hand guilloché”. Breguet has been using engine-turned guilloché dials since 1786, while this technique was still fairly new.
Although perfectly executed, each one of those dials is different. Variations can be observed with the secret signature, or the spacing between the parallel strips of Paris stud pattern.
(For the sake of transparency, note that the title “guilloché main” may apply equally to a fully hand-made work, or to “numerical control guillochage” with the help of an automated machine tool. Maybe this label could use a stricter definition. As far as I know, and according to their literature, Breguet is using the same techniques and machines as they did centuries ago.)

The dial uses those different surface finishes:

All those particular patterns catch the light differently.

The Breguet hands

Like all Classique models for the last few centuries, the 5157 uses a specific type of hands bearing a small circle near their tip.

Macro aiguilles No illustration yet.

This type of hands is often called “Breguet hands” since they were introduced by the brand’s founder in 1783. Many other firms have been using this sort of hands as well; when they do, they usually refer to this design as “pomme” hands (French for “apple”).

Niter bluing is the name of a non-chemical process used to harden steel at high temperatures. With the help of careful human supervision, a steel part can turn to “peacock blue” when exposed to heat. While the early watchmakers used fire, parts such as hands and screws are now usually blued inside an oven.
After using gold hands for many years, Abraham-Louis Breguet observed that blue hands were easier to read against a light dial. Those blued hands, yet another advancement in his quest for a better legibility, have become so emblematic that they are currently used as the brand logo.

Breguet logo No illustration yet.

To be even more readable, the 5157 uses its dial diameter to best effect and offers two long hands. You will note that the hour hand is also slightly bolder than the minute one.
As with all models from the Classique collection, these hands are hand-finished and include no luminous paint, leaving them naturally inapt for night reading.
The hour hand travels very close to the dial, as you might expect from an ultra flat watch. It extends exactly to the inner edge of hour ring, while the minute hand stretches precisely to the small painted dots and applied cabochons indicating the minutes.

Two flat crystals

The dial is protected by a flat scratchproof synthetic sapphire, which uses a glareproof coating on the inside. It sits almost flush with the bezel — it is only a tiny bit raised, so that you can lay the watch face down and the case will not be damaged. Synthetic sapphire offers a very high transparency and has a hardness of 9 out of 10 on the Mohs scale, which makes it one of the hardest elements on Earth. It is very often used to produce glass in top-tier horology.

Much like the dial, the front crystal of the 5157 has a rather large diameter: it measures 34.5 mm across, which is quite substantial for a 38¼ mm case. You may compare this width with some 32 mm for the crystal of the Breguet Type XX (39 mm case), or 33 mm for the Breitling B-1 (43 mm case), or even the 30 mm of the Rolex GMT Master II (40 mm case).

3/4 arrière No illustration yet.

In recognition of the high quality of its movement’s finish, the Breguet 5157 is one of those watches which deserves a see-through caseback. The crystal of the back is also flat, and probably glareproofed on the inside (it is difficult to appraise the presence of a coating on a flat crystal).

The caliber 502.3

A movement of unusual dimensions

Movement compactness is generally considered a desirable trait, as this allows designing less obtrusive watch cases, or eventually packing additional functions into a base caliber. However, it takes watchmakers even more skill to develop a true flat movement — not only to produce thin gears and parts with even tighter tolerances, but also because it often requires rearranging the classic architecture of a mechanical caliber.
In the case of an “ultra” flat movement, there are usually little or no complications, as each extra level of complexity adds mechanical parts and therefore impacts thickness.

Eugénie Grandet d'Honoré de Balzac No illustration yet.

The 1970s’ quartz revolution has certainly been a game changer regarding watch dimensions. Making away with most of the elaborate parts dedicated to rate regulation and power accumulation — by the way of an electric battery and a much more precise type of (electronic) oscillator — a quartz movement can be nearly as slim as you want. For reference, the world’s thinnest quartz watch, the Concord Delirium IV, is less than 1 mm thick!

As they became less and less remarkable (as in, more and more ubiquitous), enthusiasm for thin watches wore off eventually. Then, when people got interested in mechanical watches again, in the late 1980s and early 1990s, boldness was viewed as a recognizable trait of an upmarket mechanical product. The 1984 Breitling Chronomat was a typical example of a watch with substantial dimensions.
Followed the trend for massive watches which we know today.

Part of the charm of the 5157 is its unusual size in the current marketplace. It houses a good example of an ultra flat caliber, called Breguet 502.3, with dimensions of 27.9 × 2.4 mm. This diameter would make it fit for smaller watch cases too; for instance, a variant is found inside the 34 mm Blancpain Villeret. The 502.3 is extremely thin for a self-winding movement, which have to contain a heavy rotor. Some other ultra-slim Breguet models, like the 5967, come with a manual wind movement (this particular one being 1.9 mm thick).

Construction and specifications

An innovative architecture

The Breguet caliber 502.3 is first and foremost an ultra-flat automatic movement. It is instantly recognizable thanks to its off-centered rotor.

Schéma SVG? No illustration yet.

There is a good reason to choose such a construction. The keyless works (i.e. the system which allows to set the time and manually wind the watch) needs a winding pinion to operate perpendicularly to the movement’s plane. The diameter of this pinion therefore constitutes a bottleneck for ultra-thin calibers: a movement cannot be slimmer than this wheel, and any other part built above it, such as a rotor, would thicken the movement even more.
Frédéric Piguet ingeniously made the rotor 4 mm smaller in diameter, and relocated it to the right so that it would not be traveling over these setting and winding gears. That way, the movement’s thickness theoretically does not need to be thicker than the keyless works’.

But there is another potential obstacle to making a movement slim, which this architecture dodges nicely. In a regular automatic caliber, the rotor pivot normally sits right above the center wheel pivot, for instance on the barrel bridge. Since both are located at the center, they are stacked and therefore require additional thickness.
By putting the rotor aside, while the axis of the center wheel and cannon pinion stay at the exact center of the movement, the rotor pivot can sit directly on the main plate. No additional height is required on the barrel bridge to fit this pivot, and the rotor can operate very close to the bridges, earning some more precious fractions of a millimeter.

The complete movement consists of 140 parts, assembled to very tight tolerances.

Winding system

Being off-centered, the rotor is therefore a little smaller (and lighter) than those which use the full diameter of the movement, although it is still too large to be qualified as a “micro-rotor”; it technically remains a center rotor. It revolves on plain bearings, and is totally quiet.

The rotor is made of solid 22k gold, and color matched with the case (either white or yellow gold). With a density of 19.32 g/cm³, gold is one of the densest elements, giving the rotor an important inertia despite its slightly reduced size.

You probably already know that the term “automatic” or “self-winding” applies to a watch able to get wound from the movement of the wearer’s wrist, thanks to the rotation of this type of rotor. All this force is accumulated (with an overwinding protection) in the mainspring, which provides a power reserve of 45 hours; this means you can wear your 5157 every other day, and yet it will not stop.

The mainspring barrel has no cover, which is not uncommon for a slim movement, as a cover would add some thickness (granted, some fraction of a millimeter) on a part which is very difficult to further miniaturize.

Montre en train de charger? No illustration yet.

The caliber 502 winds clockwise on a watch winder; it is quite predictable for an ultra-slim movement to use uni-directional winding. It is also very easy to wind by hand, as the crown is not screwed, and no crown guards get in the way of your fingers.


It is probably worth mentioning that, while some other high-end ultra-slim watches (like the Piaget Altiplano’s caliber 900P) have the movement crafted directly within the case-back, the Breguet 5157 uses a classic construction where the movement is a stand-alone component which is then encased inside the watch.
It also uses traditional bridges and jewels to carry its gear train. The sight of those beautifully finished bridges makes for quite a pleasing and interesting look through the transparent case-back, even for a simple time-only watch.

The movement uses 4 main bridges: the train wheel bridge, the barrel bridge, the bridge for the automatic system, and a balance cock. All those are rhodium plated and finished consistently, anglaged by hand, and using the same Geneva waves pattern as the main plate and in the same direction, perfectly parallel.

The movement uses 35 synthetic sapphire jewels (also called red rubies); the gear train and automatic system are fully jeweled. Partly because of that, this movement has a strong torque, giving it the ability to drive the very complicated perpetual calendars.

Three Kif Elastor shock protection devices are present: one on each side of the balance wheel axle, and one on only one side of the escape wheel. This particular choice (as an escape wheel does not need to be shock protected) is sometimes used in slim movements to keep a flatter profile than would be with a traditional jewel.


The caliber 502.3 runs at a moderate 21,600 beats per hour (3 Hz). It features an annular monometallic balance, initially in copper-beryllium in the FP 70, but probably made of Glucydur in the case of the Breguet (Glucydur™ is an alloy of copper-beryllium and iron; properties of these alloys seem quite similar, as both BeCu and Glucydur are hard, non-magnetic and almost immune to temperature variation). It has a polished rim and four frosted arms, visibly poised with a laser.

One of the major peculiarities of this movement is its free sprung balance wheel. This just means that the balance wheel does not use a regulator to tune its rate. A regulator is usually a movable lever holding the balance spring (a.k.a. hairspring), which can be rotated to make the movement run faster or slower, by altering the functional length of the hairspring. It is used by a majority of movements, but the two “curb” pins of the regulator, between which the balance spring slides, have to be very carefully positioned (not too close and not too far from the spring) at the same time, in order to keep stable timekeeping. Unless this delicate operation is performed to perfection, the existence of a regulator often induces positional errors. Any relatively important shock might also throw the pins out of alignment and alter the rate significantly.

A free sprung balance wheel is a more elegant design which results in a more stable beat rate across different positions. Having no curb pins means the hairspring is free to “breathe” with its full natural length, without contact with the curb pins.
The downside of this approach is that the balance itself has to be readjusted when regulating the beat rate: this is far more time consuming than simply moving an index, like using a regulator. With a free sprung balance wheel, rate is adjusted by the means of weight adjustment screws, while the watchmaker must ensure the balance stays perfectly poised. Those screws, located on the outside of the rim, can be turned to increase (or decrease) the wheel’s moment of inertia, therefore decreasing (or increasing) its rotation speed.

In the case of the caliber 502.3, the four solid yellow gold screws are located in recessed parts of the balance wheel, so that they do not overhang, maximizing the balance’s size and aerodynamics. The square shape of the screw heads makes it easier for the watchmaker to control the rate corrections.


As is engraved on the movement, the Breguet 5157 is adjusted to 5 positions.
Adjusting theoretically consists of poising the balance wheel and correctly shaping the hairspring to reduce its gravitational effects as it expands and contracts, in order to reach a consistent beat rate between the positions of the wrist; it may also involve isochronism (i.e. avoiding a slower beat rate when the mainspring’s torque is low), and decorrelation with the temperature variations to which the watch is subjected.
(Of course, this explanation about adjustments is far from exhaustive! I am no watchmaker, and probably cannot begin to fathom all the many factors that adjusting can encompass — especially with used movements — like pivots shape problems, escapement malfunction, or even simply bad lubrication…)

Adjusting is a delicate watchmaking execution, and is usually applied only to the higher grade watches; most mechanical watch movements are not adjusted (like the Breitling Cosmonaute’s Lemania based movement where “UNADJUSTED” is engraved). Unadjusted does not actually mean that the watch does not keep good time. Adjusting is not to be confused with regulating, which is increasing or decreasing the general beat rate of the watch.

Macro "adjusted in 5 pos" No illustration yet.

The usual 5 positions tested for adjustment are: dial up (abbreviated as DU), dial down (DD), pendant up (PU), pendant left (PL) and pendant right (PR). They are, by the way, the same five positional measures used by COSC — to which is also added a temperature trial. More exhaustive positional adjustments sometimes found in high-end watches also include a sixth position — pendant down (PD).

In the case of the 502.3 movement, the temperature variations might not affect the watch too much, as the balance wheel is made of a copper-beryllium–based alloy, and its spring of silicon.

The balance spring of the caliber 502.3 has no overcoil, and therefore no specific adjustment for isochronism. An overcoil is a portion of the hairspring bent to go above the normal plane of compression and decompression of the spring. It helps shift the center of gravity of the hairspring, and even modify its torque at certain angles of its rotation. It was invented by Abraham-Louis Breguet in 1795, hence the name “Breguet overcoil” widely used across various brands.
As silicon components are produced by etching, this process makes it nearly impossible to obtain a single three-dimensional part, highly complicating the task of producing a hairspring with an overcoil. Note that the overcoil also usually adds around 1 mm of extra thickness to the balance wheel assembly, which might further explain why such a device was not selected for this ultra-slim movement. Even in the absence of an overcoil, deviance from isochronism should be reduced thanks to the many jewels which improve the efficiency of the gear train.

Movement history

In late 1967, Frédéric Piguet was granted patent 441126 for an automatic movement with off-centered center rotor. This patent describes the Caliber 70, which was the world’s thinnest automatic caliber with center rotor at the time.
It took 3 more years to refine the process of the series production, and the FP 70 was made commercially available in 1970.

The movement was slightly updated during its production period, and fitted with a new balance cock (with one less hole drilled, which makes it easier to tell which version it is), new regulator and new automatic winding rocker clutch assembly. The modified caliber 70 was produced until 1985, when it was replaced by an improved version called caliber 71, with a similar architecture but with a new mainspring barrel construction and finer toothing for some of the gears in the power train — probably the first, third and/or intermediate wheels — hence the epithet “micro-modulus” used by Frédéric Piguet.

Both the 70 and 71 are 18.000 bph, 35-jewel, 27.4 × 2.4 mm ultra-flat two-hand movements. Frédéric Piguet produced a derivative of the caliber 71 with an off-centered small second placed at 4:30, called caliber 716; this is the only evolution of this movement made by its original designer which I am aware of.

Movement No illustration yet.

The Groupe Horloger Breguet entered the Swatch Group in 1999, and Frédéric Piguet SA was also acquired by said group in 1992 (the brand name Piguet even disappeared in 2010). It is interesting to note that Breguet had been using this movement even before it was in the same conglomerate as Frédéric Piguet.

As is common practice, Breguet adopted a different name for this Piguet movement: caliber 502. Breguet used it both unmodified and as a base movement with various complications; later the movement was renamed as 502.3 when several improvements were made to its regulating organs. The frequency was increased from 18,000 bph to 21,600 bph, the regulator and smooth balance were replaced by a free sprung screwed balance, and silicon was used for the anchor horns and hairspring. There were probably no 502.1 or 502.2 versions of this caliber, as the “.3” might stand for “3 Hz” (21,600 bph). The 502.3 is exclusive to and entirely manufactured by Breguet.

The use of high-tech materials

Nowadays silicon (the 14Si metalloid, not to be confused with the synthetic polymer silicone) is quickly becoming a material of choice for the construction of several mechanical watch parts. It has been used for more than a decade now in high-end horology, and some of the most reputed brands are embracing it:

With the Swatch Group, Breguet has also been massively investing into research on silicon parts (through the Nivarox-FAR facilities) and started using flat silicon hairprings and escapements in 2006: after the calibers 777, 591A and 554.3, the 502.3 was the fourth movement to come with silicon components. Today more than 4 out of 5 Breguet movements include silicon parts.

Found inside the Breguet 5157 are a silicon hairspring and a silicon fork of the Swiss anchor lever. Both these enhancements are quite invisible to the regular observer, as the fork is hidden under the balance, and the color of the hairspring does not look different from a metal one.

Silicon has a number of advantages:

The qualities of silicon are confirmed in the high-beat movement of the Type XXII, containing a silicon anchor, hairspring and escapement wheel, allowing it to run at a remarkable 10 Hz (72,000 bph).

Movement finish

Finish is where you most expect a high-end brand to showcase its craft. The 502.3 movement found inside the 5157 shows an attractive and attentive finish worthy of Breguet’s reputation.

Photo? No illustration yet.

All three main bridges and the balance cock are decorated with impeccable Geneva waves.
Also called “fausses côtes de Genêve”, those damascened parallel patterns are — like most traditional decorations, actually — not only used to embellish a part, but also to act as a dirt trap which is simultaneously capable of hiding accidental fingerprints. There are several ways to create this delicate pattern, but conventional finishing codes require that the surface of the decorated part must remain flat.
The metal ridge in shape of a crescent, which seems as if subtracted from the rotor’s path to the left of the movement, was applied the same finish.

Cock, bridges (including the anchor bridge) and the movement’s ridge are finely anglaged.

I noticed a difference in finish between, on the one hand, a beautiful and visibly handmade anglage for the bridges, and on the other hand, a very narrow and perfectly rectilinear anglage on the side of the crescent-shaped ridge which appears so even that I first thought it to be the work of a machine. Upon additional examinations I do not rule out the possibility that it could be handmade too.

These parts also feature the brand name and the movement’s serial number in yellow gold filled “bright-cut” engravings, drawn in a style of 18th century “round hand” English-inspired italic cursive. Sign of the times, the “t” of Breguet has an additional cross stroke which was not present in older iterations of this movement, much like was observed regarding the dial logo of the modern Type XX.

Besides this, in serifed all-caps is machine-written:

Using a similar font, the reference of the movement CAL 502.3 is visible under the balance wheel.

Looking closer, one can see that the graver cuts of the hand engraving produce smooth and shiny slots, whereas the machine engraving leaves the tiny marks of the cutting tool, visible under a magnifying glass.

The hairspring stud holder has a brushed finish.

The small anchor bridge under the balance wheel is decorated with a brushed sunburst motif.

The countersinks of most jewels are chamfered and show a mirror polish; some other jewels sit flush with their bridge. The screws are beautifully finished, polished with chamfered outer and inner edges.

On the main plate is executed perlage, a well-known finish resulting in a multitude of brushed swirls, catching the light in a particular way. Perlage has similar anti-dust and anti-corrosion properties as Geneva waves, and is commonly found on both sides of the main plate of fine timepieces. It is mostly hidden under the bridges, but best visible under the balance wheel through the exhibition case-back of the Breguet 5157.

Movement macro No illustration yet.

Most wheels are five-spoked, circularly brushed and gilded. While the majority is probably made of brass or copper-beryllium alloy, some (especially small pinions) are made of steel. Their appearance is less extravagant than the bridges’, as no anglage seems to be hand applied to them.

The rotor has a brushed finish and is adorned with handcrafted circular barleycomb guilloché. (This motif is also known as “grain d’orge”, which translates to barley grain.) The rotor holds the brand name machine-engraved in serifed all-caps.

I spotted a minor oversight in the finishing of the balance cock, though. The curved chamfer near the stud holder seems raw, unfinished. Note that this is consistent across all 5157 I have seen. We might suppose that the bad accessibility of that particular surface makes it impractical to polish. (That bevel also seems to be deeper in the caliber 502.3 than it used to be in the 502.)

The overall finish of this movement is harmonious and luxurious, yet not overly ostentatious.

Movement variations

Breguet watches using this movement family

Breguet has been using this caliber for a long time in a number of timepieces, either unmodified inside slim watches, or as a base for more complicated movements. Since it is rather expensive, Breguet more readily uses it in the finer lines of their collection.

All these watches used a movement based on the caliber 502:
An asterisk (*) denotes a watch being present in the 2014 catalog

Usage outside of Breguet

Aside from Breguet, this automatic movement is also used by:

… as well as a few independent watchmakers among which stand Kees Engelbarts and Antoine Preziuso.
Seeing how many of those brands offer skeleton versions is a good indication of the beauty and fineness of the movement!

Several other brands are also believed to use this movement family, namely Cartier, Chopard, Jaquet Droz, Michel Jordi, and maybe more. You are very welcome to contact me if you have supplementary information.

Hands-on review of the Breguet 5157BA

First impressions

As a happy owner of a Type XX, I am admittedly somewhat familiar with some of the Breguet offerings; still, when trying them on, I have been amazed how refined the Classique models are, and how precious they feel. Granted I had yet to get used to gold watches — and with greater reason, coming from such a high-end watchmaker. There is nevertheless and in my humble opinion, some special aura to the Classiques, one that is hard to describe and equally difficult to imagine until you see them in person, which actually happens extremely rarely in the wild!

The first impression about a watch usually starts with its face. And what a face we have here… The silver dial of the 5157 is almost intimidating, as it is wide and uncluttered. The hour chapter ring first felt more grayish than expected, until I started to handle the watch and play with the light a little bit. Those silvered guilloché dials become alive with a ray of light (the downside being that they are hard to catch in pictures!). Add to this the blue sparkles from the hands when they are correctly aligned with the light, and what you get is a lovely, lively dial bearing many fine details to look at.

Something I surely was not expecting was how the coin edge of the case would catch the light. The “cannelures” are so thin and polished that they act as a mirror with any ray of light coming from the side. It is a rare sight and a beauty to contemplate the glints of gold coming from the sides of the watch.

Side wrist shot No illustration yet.

This Breguet certainly has uncommon dimensions, with an especially low profile for an automatic. To give you an idea, the watch is thinner than my Breitling SuperOcean’s clasp! The bezel is narrow, meaning that the watch does not look too ostentatious even though it is made of yellow gold; on the other hand, this does makes the case look large!

Turning the watch around shows a luxurious movement behind its flat sapphire crystal. The delightful handmade anglages are not lost on the eye of the onlooker, as they catch the light in a distinctive way.

In a nutshell, the 5157 is elegant, but not understated. Sure, the watch is rather simple for a Breguet, yet it is full of details. Even the dial shows a lot of depth, despite its necessarily flat silhouette.

Although I suppose some would say it is the epitome of the dress watch, others may nonetheless argue that it is a bit too large and not simplistic enough to hold this title. (If this time-only watch was actually that simple, this whole article would be shorter!)

On the wrist

Somehow the Breguet 5157 feels like my first grown-up watch; not to demean my other prized possessions, but they now tend to seem more like toys (albeit wonderful and super fun) next to the new 18k dress watch. There is undeniably something solemn about the 5157BA, and in the meantime, it comes with a delectable sensation of calm, far away from the cluttered dials, unneeded features, and obscene case diameters.

Wrist shot No illustration yet.

Everybody has an opinion regarding watch sizes; mine is that the Breguet 5157, even at 38 mm, is not a small watch. With its wide dial (making away with the outer guilloché ring seen on other models, in order to maximize the center area), slim chapter ring (to achieve the same effect) and almost flat lugs (which are not bent as much as on other Classique models, like the 3137) it was certainly never meant to look small. In fact, it even seems a little bit oversized for a traditional dress watch.

Sure, it is deliciously thin, but not in a way that makes one say “look how flat it is!”; I must admit that I did not notice it until the salesperson mentioned to me the thinness of the watch. It has a lot of presence on the wrist — certainly enough to have its wearer distracted by it from time to time! The fact that it can be tucked away safely under a cuff is simply yet another bonus.

The crocodile strap is thin enough and very supple. It is, naturally, impeccably crafted too. In accordance with their name, watches from the Classique series are usually paired with a strap of a rather conservative color such as black or brown. I chose the dark brown — but there is no bad choice in the Breguet strap catalog.
The interhorn is a convenient 20 mm which gives the opportunity to fit bands from a plethora of makers. However, as the strap is held in place by gold screws which are delicate by nature, I suppose that I will not be switching straps as often as I like to do with other watches.

On the wrist, the watch likes to be dressed up; you will enjoy matching it with your best long-sleeved dress shirts.

In operation

Wearing a watch often starts with winding its movement and setting the time: the non-screw-down crown of the 5157 pops out with a nice, frank click. The crown is rather on the small side, but has a decent grip nonetheless; the round profile of the case makes it easy to operate it.

When turning the crown, one hears a very soft sound of winding, as the pawl clicks against the ratchet wheel. The winding of the movement feels very smooth and is quite pleasant. The only thing which bothered me was a bit of slack in the hands, as the minute hand seems to be able to move freely about ±1 minute when setting the time. It makes it uneasy to set the time precisely.

As previously mentioned, the watch has no second’s hand; however, as the minute hand is fine and long, and the minute markers are very functional, it is not difficult to see if the movement is running. Naturally one could always have a peek at the back where you see the balance wheel swinging (or not) through the sapphire case-back.
The movement has no hacking feature — meaning that it does not stop when pulling out the crown — but this is actually barely needed for a watch with no second’s hand.

Barrel? No illustration yet.

One unexpected perk of the open mainspring barrel combined with the display back, is that it acts as a low-tech power reserve indicator. Indeed, a mainspring which is rolled towards the inside of the barrel means it is well wound; on the other hand, if the mainspring is resting against the circumference of the barrel, then you should give it a few turns.

The 502.3 movement runs completely quietly unless you put it to your ear. At 21,600 bph, its beat rate is not excessively fast, and somehow its pace feels consistent with the restful impression given by the watch.

The box and packaging

Likewise, the Breguet presentation box is a work of art. It is made of a beautiful walnut burl veneer with piano finish, hand crafted by Italian woodworking company Gentili Fabrizio SRL.

Box, with watch? No illustration yet.

Gentili has been producing wooden boxes for other luxury brands such as Maserati, and has also gained recognition as a cigar humidor maker.

The outside of the box shows the text Breguet - Depuis 1775 in gilded letters, while the interior is lined with signed cream-colored suede leather.

The wooden box is protected inside a thick cardboard box, which is also used to hold the various papers and literature: instructions manual, certificate of origin and warranty booklet, list of distributors, and an invitation to register your watch in the Breguet archives.

My opinion

Below is a list of the features which I preferred about the Breguet 5157BA, along with the aspects I enjoyed the less.
Although I am sure that the reader would value objectivity, you will agree that this goal is incredibly difficult to attain when talking about an über luxury timepiece (because one has objectively no need for one!) so, for once, I will not even try.

3807 + 5157? No illustration yet.

Please also let me state that I do not necessarily see any of those so-called shortcomings as a deal breaker, even at this price range: it is unavoidable to have the defects of its qualities, especially for a specialized piece such as an ultra flat dress watch. Having said that, I don’t think that a single timepiece on this Earth can be perfect (and I like to use it as an excuse to own several watches).



To conclude

By now, you might probably agree with me that this Breguet Classique is more than just a watch: it is a breathtaking work of art to place on the wrist. With all due modesty, one can consider it as an interpretation of what a fine luxury timepiece should be like. It is built to stand the test of time, and is an heirloom piece in its own right.

The Breguet 5157 possesses the inner and outer beauty expected from a “haute horlogerie” piece. While it is a time-only watch and one of the simplest models from its line-up, yet its simplicity gives its dial a pleasantly balanced design and a timeless elegance. Subscribing to the principle that “less is more” enhances the overall legibility of the watch and underscores its outstanding quality of production.

I find myself also looking at the movement a lot, mostly with the naked eye, but it is extremely tempting to reach out for the 10× loupe and dive into the intricacies of this cleverly constructed automatic caliber.
At first I had assumed that an ultra flat movement would be less interesting than a regular one, however this surmise was ill-founded. Again, from a layout standpoint, it is hard to tell if it is ultra flat; moreover, most likely thanks to the applied finish, it looks very three dimensional.

I chose the yellow gold version because it is the color which most resonates with the classic nature of the 5157. On the other hand, yellow gold is certainly more likely to get attention than white gold; as I do not work in a rather informal environment, I would probably find myself wearing the 5157 a bit more if it was made of white gold. (I have no regrets nevertheless!)

On the wrist, this 38 mm watch wears like a 40 mm one — mostly due to the jutting and almost flat lugs which make it look larger, and naturally also because of the wide silver dial.

That said, the watch measures a reasonable 44 mm between the lugs’ extremities, but I think that with my rather small wrist of 16 ¾ cm (6.6 in), the watch needs to be very correctly centered so that lugs do not extend past the edge of the wrist. In order to accomplish this precise positioning, one would need to fasten the strap tight. At this point, a deployant clasp would probably be a sound investment, as it goes easier on the strap than a traditional tang-type buckle.

To conclude, let me say that, even after one full year of ownership, the Breguet Classique 5157BA still fascinates me and impresses me a lot, since it belongs to a group of the finest timepieces I could dream of. In all honesty I don’t know if it looks good on my wrist, and somehow I need(ed) quite some time to really get used to its dimensions. Anyway, I always have a thrill of pride and delight just by looking at it.

My Breguet Classique

Fact sheet

Model nameBreguet Classique 5157
Case diameter38 mm (1.50 in) excluding crown
Case thickness5.35 mm (0.21 in)
Movement typeself-winding
Power reserve45 hours
Weight32 g (1.13 oz)
MSRP (2013–2014)15,100 € in yellow gold; 15,900 € in white gold


Breguet ran an auction through eBay in late 2010 in favor of the New York Philharmonic School Partnership program. The watch presented was the 5157BA. For the curious, it got sold for just a couple hundred US dollars shy of MSRP.


Breguet watches are usually not seen very often in real life, but the Classique 5157 has been spotted on the wrist of a couple of famous people: